There's absolutely no reason to use Betterment or Wealthfront anymore, though bloggers with endless referral links won't give you the real deal.
http://www.etf.com/sections/blog/schwab-intelligent-portfolios-x-ray?nopaging=1 <--- comparison between the "Big Three".
https://intelligent.schwab.com/ <---- take the questionaire and see the recommended allocation.
A.) If you believe in the Fama-French 3 factor theory, it makes sense to tilt towards the small premium AND the value premium - Schwab has a lot more in Smalll than Betterment and Wealthfront do
B.) The stock heavy allocation is 94% stocks, 6% cash. On a $50k portfolio, the amount in cash is $3500. The opportunity cost of having that $3500 cash in an online savings account is roughly $35 less taxes. This essentially equates to 7 basis points in fees which is significantly less than Betterment or Wealthfront.
C.) The fundamental indexes are basically a value tilt. What's different about them than a straight value fund is that 1) they include more holdings from less valuey sectors - so they aren't as sector shifted as value funds and 2) they will adjust their value exposure based on the valuation difference between growth and value. So as growth outperforms, they will increase exposure to value, and if there is a small spread between value and growth, they will be less value oriented. This should work if the value premium is mean reverting.
Putting in the most aggressive answers leads to this portfolio:
94% stocks, 6% cash where stocks are broken down (1st ticker primary, 2nd ticker is the TLH alternate)
US Large Company Stocks 11% - SCHX / VOO
US Large Company Stocks - Fundamental 17% - FNDX/PRF
US Small Company Stocks 7% - SCHA/ VB
US Small Company Stocks - Fundamental 11% - FNDA/ PRFZ
International Developed Large Company Stocks 9% - SCHF / VEA
International Developed Large Company Stocks - Fundamental 13% - FNDF/PXF
International Developed Small Company Stocks 4% - SCHC / VSS
International Developed Small Company Stocks - Fundamental 6% - FNDC / PDN
International Emerging Market Stocks 4% - SCHE/ IEMG
International Emerging Market Stocks - Fundamental 6% - FNDE / PXH
US Exchange-Traded REITs 4% - SCHH / VNQ
International Exchange-Traded REITs 2% - VNQI / GQRE
The funds used to make this portfolio:
I would have absolutely no issues using the above as my equity allocation in a taxable account and putting my fixed income in a combination of tax exempt bond fund, rewards checking, total bond market index, etc.